/*
Demonstration of traversing an array from both ends at the same time
in idiomatic TypeScript, with explicit variable types.
We use the classic "two‑index" technique:
- left: number → starts at index 0
- right: number → starts at index arr.length - 1
Both move toward the center.
This approach is efficient (O(n)), simple, and widely used in
algorithms such as palindrome checks, partitioning, and pair searching.
*/
// ------------------------------------------------------------
// Function: traverseFromBothSides
// Purpose: Traverse an array from both ends simultaneously.
// ------------------------------------------------------------
function traverseFromBothSides(arr: number[]): void {
let left: number = 0; // left index
let right: number = arr.length - 1; // right index
// Move inward until the indices cross
while (left <= right) {
console.log(`Left: ${arr[left]}, Right: ${arr[right]}`);
left += 1;
right -= 1;
}
}
// ------------------------------------------------------------
// Main program
// ------------------------------------------------------------
const array: number[] = [10, 20, 30, 40, 50, 60, 70, 80, 90];
console.log("Traversing from both sides:");
traverseFromBothSides(array);
/*
run:
Traversing from both sides:
Left: 10, Right: 90
Left: 20, Right: 80
Left: 30, Right: 70
Left: 40, Right: 60
Left: 50, Right: 50
*/
